Establishment and Characterization of Monoclonal and Polyclonal Antibodies Against Human Intestinal Fatty Acid‐Binding Protein (I‐FABP) using Synthetic Regional Peptides and Recombinant I‐FABP

Abstract We have succeeded in raising highly specific anti‐human intestinal fatty acid‐binding protein (I‐FABP) monoclonal antibodies by immunizing animals with three synthetic regional peptides, i.e., the amino terminal (RP‐1: N‐acetylated 1‐19‐cysteine), middle portion (RP‐2: cysteinyl‐91‐107) and carboxylic terminal (RP‐3: cysteinyl‐121‐131) regions of human I‐FABP, and the whole I‐FABP molecule as antigens. We also raised a polyclonal antibody by immunizing with a recombinant (r) I‐FABP. To ascertain the specificity of these antibodies for human I‐FABP, the immunological reactivity of each was examined by a binding assay using rI‐FABP, partially purified native I‐FABP and related proteins such as liver‐type (L)‐FABP, heart‐type (H)‐FABP, as well as the regional peptides as reactants, and by Western blot analysis. In addition, the expression and distribution of I‐FABP in the human gastrointestinal tract were investigated by an immunohistochemical technique using a carboxylic terminal region‐specific mo...